LTE, or long-term evolution, is a fourth generation (4G) high-performance air interface standard for wireless mobile communications. Carrier aggregation (CA) is a feature of the latest release of the LTE standard, in which user equipment (UE) is able to concurrently utilize radio resources from multiple carrier frequencies.
Uplink physical channels such as the PUSCH (physical uplink shared channel) and PUCCH (physical uplink control channel) are used to transmit information originating in layers above the PHY layer.
In the LTE release draft 10, the power headroom report (PHR) for carrier aggregation (CA) does not define how the user equipment chooses a key parameter, MPUSCH, when the PHR may be transmitted on any uplink component carrier (CC). The parameter, MPUSCH(i), is the bandwidth of the PUSCH resource assignment, expressed in number of resource blocks, valid for subframe, i.
Under carrier aggregation, due to scheduling flexibility, the PUSCH used for data transport may utilize any combination of resources from different carriers. (3rd Generation Partnership Project, Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Access (E-UTRA); Physical Layer procedures (Release 9), Version 9.1.0, March 2010, hereinafter, “3GPP specification”).
Thus, there is a need to define the parameter, MPUSCH, for the latest LTE standard.